ESM1 and glioma: Proangiogenic factors such as VEGF-A (vascular endothelial growth factor- A) and FGF-2 (fibroblast growth factor -2) also upregulate endocan mRNA and protein expression in endothelial cells, likewise in high-grade glioma cells [24] and in human renal cancer cells, whereas PI3K (phosphatidylinositol 3 kinase) has inhibitory effects [25].